Rubberlike materials and an unsaturated hydrocarbon oil



atented Get. 28, 1952 RUBBERLIKE MATERIALS AND AN UNSAIU- RATED HYDROCARBQN OIL Herman S. Bloch, Chicago, 111., assignor to Universal Oil Products Company, Chicago, Ill. a

corporation :of Delaware N Drawing. Application June 30., $48.,

Serial No. 36,262

11 Claims. (01. cruisers) This application is a continuation-impart of my copending application Serial Number 556.649 filed September 30, 1944, now abandoned;

Thi invention relates to a process for producing and employing a hydrocarbon material useful as a plas'ticizer and extender for rubber. More specifically, this invention is concerned with the production of vulcanized rubber-like composites comprising essentially a rubber, sulfur, and a hydrocarbon formed by treating aliphatic hydrocarbons with hydrogen fluoride.

An object of this invention is the production of a rubber plasticizer from the hydrogen fluoride catalyst layer used in conversion reactions of aliphatic hydrocarbons.

Another object of this invention is to produce a plasticizer and extender for rubber by reacting at least one aliphatic hydrocarbon selected from the group consisting of isoparafiinic and ol'efinic hydrocarbons in the presence of "liquid'hydrogen fluoride.

A further object of this invention is to plasticize a rubber selected from the group consisting of natural rubber and synthetic rubber by incorporating therein a hydrocarbon material boiling above about 150 C. and obtained from a hydrogen fluoride layer which has catalyzed the alkylation of an isopara'fiflnic hydrocarbon by an olefinic hydrocarbon.

A still further object of this invention is to plasticize a rubber by incorporting therein a hydrocarbon mixture deriyed'from "material boiling above about 150 C. obtained by reacting an olefinic hydrocarbon having at'least three carbon atoms per molecule in the presence of hydrogen fluoride containing less than about by weight of water at a temperature of from about 0 to about 150 C. One specific embodiment of this invention comprises a process for plastic'izing a rubber selected from the group consisting of natural rubber, butadiene-styrene copolymers, butacliene-acrylonitrile copolymers, and butadiene-isobutylene copolymers, which comprises incorporating therein a plasticizer selected from the'group consisting of (1) a polyolefinic cyclic hydrocarbon residue containing conjugated unsaturation and produced by reacting in the presence of liquid hydrogen 'fluoride at a temperature of from about 0 to about 150 C. at least one aliphatic hydrocarbon selected from the group consisting of isoparaffinic and oleflnic hydrocarbons, separating theresultant reaction products into a hydrocarbon layer and a hydrogen fluoride layer, recovering a substantially fluorine-tree hydrocarbon material 2 from said-hydrogen fluoride layer, and removing from said last-named material the'hydrocarbons boiling below about 0. to leave said residue, and (2) the reaction product of sulfur with :said hydrocarbon residue.

Another embodiment bf this invention relates to a process for plasticizingarubber-like material which comprises incorporating therein fromabout 5 to about 30% by weight of a hydrocarbon mixture boiling above about; 1 50 C. and produced by reacting an oleiinic hydrocarbon having at least 3 carbon atoms per molecule with liquid hydrogen fluoride at a temperature of from about 0 to about 150 C;

For sometime it hasvbe'en recognized that th workability of nal ll al'rubber and synthetic polymers usable as rubber'subs titutes is improved by ulast c i g a d s ften n hese b m terials before subjecting them to millin "molding, and vul g. o erat onssyn het c pol mers andnatural rubber have -beenp lasticized by add.- ing thereto substances such as oils, fats, waxes and the like, including tars, high molecular weight hydrocarbonsrecovered from sulfuric acid-hydrocarbonsludges, solvent extracts of petroleum oils, residues from theclay-treat'ing of petroleumfrac tions and the like, Use of the aforementioned plasticizers causes the rubber-like materials to flow more easily accordingly to process more v a ously in i -lins and in r tions- However, man o he pre ious ilsed plas ic ze s .clo mi e es s lfiielen plasticization of t ru be yma er als a dr meti-ln s-s-ir 1 desirable properties to,t afinlshes r edup a ,70 example, some plasticizers re bjectionable in odor, color, or in their rinfluenceupon the tensile strength and elong tion o the fini hed u b r product.

A methodof; the prior art-relate to treating cracked gasoline with-0.1 to 6%, of its Weigh-t of substantially anhydrous whydrogen fluoride to remove readily oxidizable and polymerizabieconstituen'ts which tend to readily :form sums storage without removing any substantial proportion of monoolefinsf As this treatment removed from theicracked .gasoline son-1y con.- stituen-ts more easily polymerizable than the monooleflns, it is evident that the resultant poly merized constituents were different in chemical composition from'my plastio'izer oil which is re.- covered from a hydrogen fluoride layer containingcon-j unct polymerder'ived from a monoolefi-nic or isoparaflinic hydrocarbon which has been contactedwith from lb to I000% and preferably-from 3 about 30 to about 65% of its weight of liquid hydrogen fluoride.

I have obtained a hydrocarbon product which is useful, not only as a plasticizer, but also as an extender in natural rubber and synthetic rubbers. The term extender as herein employed refers to a substance which may be admixed with natural rubber or synthetic rubber to increase the volume and weight of the finished rubber-like material without affecting appreciably the desirable characteristics of the rubber-like material. Accordingly, the material employed as extender should preferably covulcanize with the natural rubber, synthetic rubber, or mixtures of these materials.

Monoolefinic hydrocarbons utilizable in producing the plasticizer employed in this process have at least three carbon atoms per molecule and comprise propylene, the butylenes, pentenes, hexenes, heptenes, octenes, and higher boiling monoolefinic hydrocarbons. Of these materials, propylene has been found to require the higher portions of the catalystzolefin ratios and of the temperature range cited for its satisfactory reaction, While the higher oleflns undergo reaction even in the lower portions of the ranges of these variables. A preferred source of monoolefinic hydrocarbon is polymer gasoline which is formed, for example, by polymerizing propylene and butylenes or mixtures thereof in the presence of solid phosphoric acid catalyst, which is a calcined composite of a phosphoric acid and a siliceous carrier such as diatomaceous earth, also called kieselguhr. Fractions of cracked gasoline containing substantialamounts of olefins and relatively small proportions of aromatic hydrocarbons are also suitable charging stocks. These gasoline charging stocks may also contain certain amounts of paraffinic and naphthenic hydrocarbons some of which may be alkylated during the polymerization treatment. C3 and C4 fractions recovered from the products of cracking and a C4 fraction recovered from butane dehydrogenation and containing mainly butylenes and normal butane with relatively little isobutane are also good charging stocks for this process.

Olefinic hydrocarbons having more than three carbon atoms per molecule are more desirable as charging stocks than propylene because of the increased yield of both saturated and unsaturated liquid products and improved properties of the products obtained from these preferred charging stocks, as well as because of their greater ease of reaction. About the same quantity and quality of plasticizer oilare obtained when charging any of the olefins having from 4 to about 12 carbon atoms per molecule. The different monoolefins having at least four carbon atoms per molecule appear to be mutually interconvertible by polymerization and depolymerization reactions at the conditions specified for this process. a

' Other unsaturated hydrocarbons which may be used in producing the plasticizer ofthis proc- 4 comprise isoparafiinic hydrocarbons or hydro carbon mixtures containing substantial amounts of isoparaflinic hydrocarbons, preferably together with olefinic hydrocarbons. The isoparafiinic hydrocarbons may vary in molecular weight but it is frequently advantageous to employ a mixture of branched-chain parafiinic hydrocarbons boiling above about 150 C. For example, a material rich in higher boiling isoparafiinic and other branched-chain paraffinic hydrocarbons may comprise the higher boiling fractions of products formed by the alkylation of an isoparafiinic hydrocarbon with a monoolefinic hydrocarbon to form aviation gasoline. Such hydrocarbons boiling higher than aviation gasoline may be used as such or selected fractions thereof, such as the 150-200 C. or 200-450 C. fraction, may be reacted with hydrogen fluoride at a temperature of from about 30 to about 150 C. to form a still higher boiling hydrocarbon material, the latter utilizable as a plasticizer. The isoparaffins require a somewhat higher reaction temperature than oleflns, since the former must first be cracked to olefinic fragments before conjunct polymerization can take place.

Hydrogen fluoride catalysts employed in this process and also referred to as hydrofluoric acid contain a major proportion by weight of hydrogen fluoride and generally may contain as much as 10% by weight of water, although the titratable acidity of the catalyst layer may be less than because of the presence therein of dissolved organic compounds including highly unsaturated materials which are described more completely hereinafter. The catalyst preferred in this process is substantially anhydrous hydrogen fluoride. that is, hydrogen fluoride, or the hydrogen fluoride of commerce, of 98+% purity.

The process for producing the plasticizer 011 comprises essentially reacting an aliphatic hydrocarbon selected from the members of the group consisting of isoparaflflnic and olefinic hydrocarbons in the presence of liquid hydrofluoric acid at conjunct polymerization conditions which include a temperature of from about 0 to about C. and a pressure sufficient to maintain the reactants and hydrogen fluoride catalyst in substantially liquid phase, separating the resultant upper saturated hydrocarbon layer from the lower hydrogen fluoride sludge layer, and then decomposing the hydrogen fluoride sludge layer by water hydrolysis, by heating or by another suitable method to recover the plasticizer oil therefrom. The weight ratio of hydrogen fluoride catalyst to aliphatic hydrocarbon charging stock, that is, the isoparafilnic, olefinic, or com-' bined mixture of isoparafiinic and olefinic hydrocarbons will vary from about 0.1 to about 10. When the hydrogen fluoride to aliphatic hydrocarbon weight ratio is less than about 0.1, it is necessary to recycle excessive amounts of the hydrocarbons in order to obtain good conversion, while increases in this ratio above about 10 effect very little further increase in yield of the desired reaction products but such increased ratio of hydrogen fluoride to the total isoparafiinic and olefinic hydrocarbons does descrease the capacity of the reactor and other treating equipment.

When isoparaffinic, olefinic, and mixtures of isoparafilnic and olefinic hydrocarbons are contacted with hydrofluoric acid catalyst containing less than about 10% by weight of water, a complex series of reactions occurs which is herein referred to in the aggregate as a conjunct polymerization reaction. This conjunct polymeriza- 5. tion reaction comprises an initial polymeriza-e tion and condensation reaction between the hydrocarbons present in the reaction mixture and as the reaction progresses further, cyclization and isomerization of the polymers occur, accompanied by a hydrogen transfer reaction between the various hydrocarbons and conjunct polymers present in the reaction mixture whereby part of the conjunct polymers are converted into saturated hydrocarbons by Virtue of the hydrogen transfer at the expense of other com onents which are converted into highly unsaturated hydrocarbons containing on an average of from about '2 to about 4 double bonds per molecule of which from about 40 to about 70% are conjugated. The resulting unsaturated con'junct polymers comprising a series of high molecular weight polyolefinic cyclic hydrocarbons become attached by weak chemical bonds to the hydrogen fluoride catalyst to form a sludge-like complex addition product in which fluorine is not, however, organically bound, since it can be substantially all recovered by treatment of the complex with water or with cold aqueous alkali. The saturated hydrocarbon conjunct polymers form a hydrogen fluoride-insoluble phase which upon settling of the reaction mixture separates as a distinct upper layer which is, separated readily from the lower hydrogen fluoride layer in which the highly unsaturated polyolefi'nic cyclic hydrocarbons are contained. I

It is of interest to note that in this type of copolymerization, in which hydrogen transfer occurs, the product recovered from the sludge or catalyst layer has a higher molecular weight than the charge stock, and is generally more unsaturated than the charge stock.

As the saturated hydrocarbons of the upper layer boil over about the same range oftem- .perature as do the unsaturated plasticizer oil constituents recoverable from the hydrogen fluoride lower layer and as small amounts of the saturated hydrocarbons are entrained or mixed with the hydrogen fluoride "lower layer, it "is ad'- visable to extract the hydrogen fluoride, lower "layer with a low "boiling saturated hydrocarbon, preferably a paraii'in having from '3 to about 8 carbon atoms per molecule, before hydrolyz'i'ng, or otherwise decomposing, the -h'yt'irogenfluo'r'i'de lower layer to recover the unsaturated drying oil therefrom. From the lower layer, the hydrogen fluoride and 'plast'ici'zer oil fractions are "then separated by suitable means, for example, the lower layer maybe added "to water or ice whereby the hydrogen fluoride is dissolved in water to form an aqueous solution from which the plasti- "ci'zer oil se arates as an upper layer. Also the lower layer may be subjected to flash distillation to v'ap'orize the hydrogen fluoride from the higher boiling highly unsaturated plasticiz'er oil. When "the lower layer is separated by distillation methods, the recovered hydrogen fluoride 'is suitable for recycling to the process to effect reaction of additional "quantities of "charged 'monoolefini'c hydrocarbons.

Passage of inert gas, such as nitrogen, hydrogen, "methane, ethane, carbon dioxide, and the like through the distillation system in which the hydrogen fluoride is being separated, assists in the recovery of the highly unsaturated plasticizero'il. Separationof hydrogen fluoridefrom the plasticizer oil present in the lower layer is also assisted by carrying out the flash distillation of said lower 'layer in a tower "containing catalytic "packing material formed from "graphitlzed carbon or from a metal selected from the members of the group consisting of aluminum, copper, cobalt, lead, cadmium, and an alloy of copper, such as brass, and preferably in the presence of an inert carrier gas to assist in re-- moving the liberated hydrogen fluoride.

Another method of decomposing the hydrogen fluoride-plasticizer oil mixture of the lower layer formed by the conjunct polymerization of olefinic hydrocarbons in the presence of hydrogen fluoride, is to introduce the lower layer or sludge into an inert liquid, :such as :-a paraiflnic hydrocarbon contained in :a decomposition zone and maintained at a temperature near its boiling point. The decomposition zone or re'act'or tower may contain a catalytic packing material in the liquid *zone of this r'eactor tower and an inert gas may also be passed thereth'rough. Hydrogen fluoride so liberated is vaporized, condensed, and conducted to storage while the inert liquid containing the dissolved, highly unsaturated plas ticizer oil is withdrawn from the decomposition zone, either intermittently or continuously, and replaced by fresh liquid. This liquid should be readily separable from the plasticizer oil dissolved therein, and it should also be relatively inert to the hydrogen fluoride sludge and to the products of the decomposition of the sludge. If a paraflinic naphthais employed, its normal boiling point should be from about 100 to 150 C., so that it may be separated by fractional distillation from the plasticizer oil which boils generallyifroim about 150 to about -ii50 C.

Another source of rubber lasticizer is the hydrogen fluoride catalyst layer which is recovered from an alkylation process in which aviation gasoline is formed by reacting an isopar-afiinic hydrocarbon with a monooleflnic hydrocarbon such as a butylene or normally liquid monooleflnic hydrocarbon. When such an :alk-ylation process is conducted for some time in the presence of a hydrogen fluoride catalyst, a substantial proportion of organic material accumulates in the hydrogen fluoride catalyst layer and may be recovered therefrom by suitable means. For example, the used hydrogen fluoride catalyst may be subjected to fractional distillation to separate therefrom hydrogen fluoride and leave as a residue a relatively high boiling hydrocarbon material. The organic material may also be separated from the used hydrogen fluoride catalyst by treating the used catalyst with water whereby a hydrocarbon layer separates from the aqueous hydrogen fluoride. The resultant hydrocarbon material may be used as such as a rubber plasticizer, but I prefer to subject it to fractional distillation to remove therefrom the relatively low boiling hydrocarbons so as to recover organic material of higher molecular weight frequently having the characteristics of a resin which I have found to be suitable for mixing with natural rubber and various synthetic rubbers.

Study of the ultra-violet and infra-red absorption spectra and other properties of plasti 'clz'er oil fractions formed from polymer gasoline and boiling from about 150 to about 290 C., shows that these hydrocrabons are non-aromatic and that most of them contain a pair of conjugated double bonds with one of these double bonds in a ring of five carbon atoms and the other double bond in an alkenyl side chain. Thus a cyclopentene ring may be combined with a methylene groupnor a vinyl group. However,

some of the plastici'zer oil hydrocarbons which aemsse contain a cyclopentenyl ring also contain more than two substituent groups but each of these groups is highly substituted. The higher boiling fractions of this plasticizer oil boiling up to about 450 C. contain non-aromatic, polycyclic, polyenic hydrocarbons which are generally bicyolic. In both the monocyclic and polycyclic hydrocarbons the five-carbon atom ring portions of the molecules are combined with at least two alkyl groups. or two unsaturated aliphatic groups. The data obtained on these fractions indicate that one of the double bonds comprised by the conjugated diene systems of the plasticizer oil is within a five-carbon atom ring and the other double bond is in an alkenyl or, alkapolyenyl substituent. Alkapolyenyl groups that may be present are highly branched and contain isolated unsaturation as well as conjugated unsaturation. Some of the typical hydrocarbons contained in the plasticizer oil mixtures so produced from polymer gasoline are represented structurally by the following formula:

R R R9 o R3 R1 I I RCUR4 wherein the radicals R to R are selected from the group consisting of hydrogen and alkyl, alkenyl and alkapolyenyl hydrocarbon radicals, at least two of the substituents R to R are bydrocarbon radicals, and not more than two of the groups R to R represent hydrogen.

Other constituents of the plasticizer oil formed from polymer gasoline are believed to have structures that may be represented by the formula:

wherein R to R represent members of the group consisting of hydrogen and alkyl, alkenyl, and alkalpolyenyl hydrocarbon radicals, at least two of the substituents R to R are hydrocarbon radicals, and not more than two of the substituents R to R are hydrogen.

The unsaturated poylcyclic hydrocarbon plasticizer oil formed as hereinabove described and utilized in this process, differs in many ways from the unsaturated hydrocarbons heretofore recovered from sulfuric acid sludges recovered during petroleum refining and described as rubber compounding agents or plasticizers. Differences observed in the ultra-violet and infra-red absorption spectra of these types of plasticizer oils are given in Table 1. In order to interpret the results of the ultra-violet absorption spectra, use is made of the specific extinction coefficien indicated in the table as E." The term specific extinction co-eificient is defined by the following equation:

Iso-octane, more exactly known as 2,2,4-trimethylpentane, is employed as the solvent since this octane gives substantially no ultra-violet absorption in the wave length examined.

Also the symbol Amx is used to refer to the wave length at which the maximum absorption of ultra-violet light occurs.

TABLE 1 Ultra-violet and infra-red absorption spectra of hydrocarbon plasticizers Plasticizer recovered Plasticlzer of Example from petroleum hyl boilingabove 320 C. drocsrbon -sulfuric acid sludge Ultraviolet absorption spectra:

Amnx- 50 1 1] ml]. xQIQIIIIIIII .--IIIIIIIIIIIIIIIIIIII 25am...

Absorption due el- Dominant absorption almost entirely to is that of aromatic non-aromatic conjucompounds. gated diolefin. Inn's-red absorp- There is comparatlve- There is comparatively tion spectra. ly weak absorption strong a bsorptlon with generally sharp with generally broad bands, and evidence band s, some of which of the complete lack are assignable to aroof aromatic commatic compounds, pounds.

The data on the ultra-violet absorption given in Table 1 show that the plasticizer of this process has a single absorption maximum at a wave length of 250m while the plasticizer recovered from sulfuric acid-petroleum hydrocarbon sludge has two ultra-violet absorption maxima, namely, at 230m and 258m. Accordingly, from these data it is concluded that the predominant ultra-violet absorption originated in these two plasticizers in entirely different types of compounds. Ultra-violet absorption observed in the plasticizer of my process is due to nonaromatic conjugated diolefin compounds while that obtained on the plasticizer recovered from petroleum hydrocarbon-sulfuric acid sludge is due to aromatic compounds.

The unsaturated polycyclic hydrocarbon plasticizers of my process also difier in many other ways from the unsaturated hydrocarbon plasticizers recovered from sulfuric acid refinery sludges. These two types of plasticizers difier in the types of hydrocarbons present therein, the percentages of carbon and hydrogen, the molecular weights, and the degrees of unsaturation, as indicated by the comparative results given in Table 2.

The plasticizer oil of the present process is a sweet-smelling material ranging in color from light yellow to dark brown and on exposure to air dries to a solid film. It has an average molecular weight of from about 250 to about 500, although oils having molecular weights of as low as about to as high as about 1000 have been prepared, these oils comprising compounds of substantially the same homologous structure and chemical properties. These properties in- TABLE 2 Physical and chemical properties of hydrocarbon plasticizers Oolumn No l 2 A plasticizer 1 recov- Plasticizer of Example cred from petroleum l boiling above 320 C. hydrocarbonsulfuric acid sludge Formula (OHIJS): CQMHn-z 1-32): zi-9 33.2

CnH2n 7-fi J n 2n l6-B (Av.). (Av). Analysis: I

Percent Car- 87.4 90.

bon. Percent Hy 10.

drogen. Mol. Wt 390 3001,000 (Av. 400). Structures Cyclo-polyenic Polycyclic aromatics. Drying Properties. Dries Non-drying. Iodine No (264) 40-60. Bromine N0 166 (25-38). Maleic Anhydride Value. Acid No 0 0. Saponification No. 0 0. Olefinic Double Bonds per Molecule:

Total (based 4 2 on bromine number). Conjugated- 1.7 Color (Reddish yellow 17 Red-Brown.

Gardner) These data are taken also from the article by Fritz Rostler and Vilma lllehner, India Rubber World, August 1, 1941, pp. 47-51, and tlge article by L. Bernstein and F. Rostler, Modern Plastics, April 1 42. v

2 Equiv. of Br No.

3 Equiv. of Iodine No.

0.327 to about 0.335, and carbon to hydrogen atomic ratios close to 1:1.7.

The relatively high molecular weight hydrocarbons which are so formed by treating analiphatic hydrocarbon or aliphatic hydrocarbon mixture with liquid hydrogen fluoride are highly unsaturated and are co-vulcanizable with rubber. I have found also that these unsaturated hydrocarbon materials will dissolve or react with at least 40% by weight of sulfur, forming products which range from viscous oils to hard brittle solids, depending upon the sulfur content.

Mixtures of the cyclic polyenic plasticizer with sulfur react only sluggishly at 150 C. and somewhat more readily at 200 0., but at 240 0., the reaction is rapid and smooth.

In general, a composite of a sulfur-vulcanizable rubber and my highly unsaturated plasticizer requires a larger amount of sulfur for vulcanization than that used heretofore with rubber compounding mixtures containing no plasticizer or containing a plasticizer of the prior art such as those derived from sulfuric acid sludges recovered from the treatment of hydrocarbons. The amount of additional sulfur preferred (in excess over the amount normally used with the rubber) is approximately 1 part sulfur per every 10 parts plasticizer added to each 100 parts of rubber. If the sulfur is added as a solution in or as a reaction product with the plasticizer, the ratio of sulfur to plasticizer may be readily adjusted so that all of the sulfur required by the rubber-plasticizer composition is contained within the amount of .5 below about 145); specific refractions of about i0 plasticizer that is added to the rubber. This is readily shown by'the following table:

Q I Extra Sulfur v Percent Plsitigi zer sllfil li i 'fil for Plasfi" S ii i Sulfur in Per 100 Parts cizer, Parts P t Plasticizer a Per 100 g Required" ni t r Parts Rubb er (Based Rubber Plasticizer) 10 3 I 4 40 2O 3 2 5 25 3O 3 3 6 20 When such a composite of unsaturated hydrocarbon mixture and sulfur is heated tojform a viscous fluid, and the latter is admixed with natural rubber or synthetic rubber, .the sulfur'is dispersed readilyand uniformly throughout the mass of rubber-like material.. In addition to this advantage of aiding in themixing of sulfur with rubber, the unsaturated hydrocarbonaceous material described above also has a softening and plasticizing effect to make the rubber or rubberlike material more workable in rubber treating equipment.

The plasticizer and extender referred to herein may be applied to an elastomer selected from the group comprising natural rubbers and synthetic rubber-like polymers comprising diene polymers and copolymers of dienes with monoolefinic monomers. These various elastomers include not only natural rubber but copolymers of butadiene with at least one member selected from the group consisting of styrene, isobutylene, and acrylonitrile. The term a rubber is employed in this specification and in the claims in a general sense to include caoutchouc, reclaimed rubber, balata, gutta percha, rubber isomers, and like products whether or not admixed with fillers, pigments, vulcanizing or accelerating agents. This product may also be used in the reclaiming of vulcanized rubber in which case the plasticizer is not separated from the reclaimed rubber but both materials are utilized in admixture.

The following examples are given to illustrate the character of results obtained by the use of specific embodiments of the present process, although the data presented are not introduced with the intention of unduly restricting the generally broad scope of the invention. I

EXAMPLE 'I' j During a period of 94. 5 hours, a total of 109 kg. of polymer gasoline. was contacted with 35.6 kg. of hydrogen fluoride at a temperature :of 78 C: and at a pressure of 10.7 atmospheres. During this run, the charging rates of polymer gasoline and hydrogen fluoride were 1610 and 381 cc. per hour, respectively, through a reactor of 1300 cc. capacity. The-ratio of the volume of polymer gasoline to the hydrogen fluoride was thus 4.2. The average time during which the polymer gasoline was in contact with the hydrogen fluoride was about 39 minutes; The reaction mixture so obtained consisted of 90.7 kg. of an upper hydrocarbon layer and 44.3 kg. of a hydrogen fluoride layer, the latter containing some organic compounds. The hydrogen fluoride layer on treatment with ice water followed by washing of the separated oil with caustic soda solution and filtering through a column of soda-lime and anhydrous barium oxide yielded 16.? kg. of a clear oil which gave a neutral reaction when shaken with water and an indicator and was substantially fluorine- The hydrocarbon oil mentioned above was then distilled to remove the lower boiling hydrocarbons, leaving in the still the higher boiling 50% of the hydrocarbon oil. The material remaining in the still which was used subsequently as a rubber plasticizer, had the following properties:

(14 0.872 Boiling range at 760 mm. Hg above 320 C. Color (Gardner) 1'7 Viscosity (25 C.) poises 6 Bromine Number 166 Molecular weight 390 Double bonds/mol. (by Br No.) 4

The plasticizer prepared as above described was then compounded with butadiene-styrene cpolymer, (GR-6) according to the following standard formula: 100 g. of GR-S, 50 g. of carbon black (Kosmobile 77), g. of zinc oxide, 1.5 g. of mercaptobenzothiazole, 20 g. of plasticizer, and sulfur, the latter added in amounts of 2, 3, 4, or 5 grams in separate tests. The composites prepared according to this test formula were then vulcanized at 140 C. for 90 minutes. The composite containing 5 parts of sulfur per 100 parts of GR-S which was superior to the other composites had a tensile strength of 2440 pounds per square inch at break, a modulus of 1150 pounds per square inch at 300% elongation, and an elongation of 495%.

EXAMPLE II (24 Bromine number 101 Acid number 0.4 Viscosity (25 C.) poises 3,350

Molecular weight 379 Diene value 8.7 Conjugated double bonds/mol 0.26- Color (Gardner) 18 The above mentioned hydrocarbon mixture was then used as a plasticizer in the standard test formula referred to in Example I. A composite containing 100 parts by weight of GR-S, 50 parts of carbon black, 5 parts of zinc oxide, 1 part of mercaptobenzothiazole, 20 parts of hydrocarbon plasticizer, and 5 parts of sulfur after curing for 50 minutes at 140 C. yielded a rubber with a tensile strength of 2400 pounds per square inch at break, an elongation of 505%, a modulus of 810 at 300% elongation, a hardness of 60 by the Shore method, and an elasticity of 68% by the Shore method.

EXAMPLE III Tests were made using the high boiling hydrocarbons described in Examples I and II, as plas- 12 ticizers for butadiene-styrene copolyrner generally referred to as GRr-S. These results are also compared with similar information obtained in another series of runs utilizing a highly aromatic plasticizer recovered from sulfuric acid sludge formed during treatment of lubricating oil with sulfuric acid. In each of these tests, the standard test mixture contained grams of butadiene-styrene copolymer, 50 grams of carbon black, 5 grams of zinc oxide, 1.5 grams of mercaptobenzothiazole, 20 g. of plasticizer, and sulfur in an amount of 2, 3, 4, or 5 grams. Samples containing the different plasticizers were vulcanized at C. for 50 minutes, and other samples containing the plasticizers of this application were also vulcanized at 140 for 90 minutes. Results obtained in this comparison are given in Table 3.

TABLE 3 Properties of vulcanized GR-S containing 20 per cent of plasticizer- PLASTICIZER OF EXAMPLE I I Vulcani- 5 5: I, zation Tsntsfle Elonga- Modulus Hard- Elas- I 100 J Time, Bria}: tion, at 300% ness ticity GER $t S f Percent Elong. (Shore) (Shore) I a 50 1, 500 800 s50 53 50 l 4 50 2, 000 080 450 51 51 g 5 50 1, 700 500 500 58 55 3 90 2, 400 500 4 00 2, 240 505 900 5 so 2, 440 495 1, 150

PLASTICIZER 0F EXAMPLE II a 50 1, 500 700 350 55 0s 4 50 2, 440 705 000 as 03 1 5 50 2, 400 605 00 as 4 0o 2, 280 440 1, 050

PLASTICIZER RECOVERED FROM LUBRICATING OIL-SULFURIC ACID SLUDGE 3 50 2, 000 440 1, 050 54 as 4 5o 1, 050 330 1, 000 57 10 5 50 1, 550 240 70 50 From the results given in Table 3, it is seen that vulcanized GR-S of approximately the same tensile strength but greater elongation was produced when using the plasticizer of Example I as when a plasticizer recovered from lubricating oilsulfuric acid sludge was tested similarly. The vulcanized GRr-s of Example II was superior in tensile strength and elongation to that containing plasticizer recovered from lubricating oilsulfuric acid sludge and using 50 minutes time of cure while the plasticizer of Example I gave better results when using a vulcanization curing time of 90 minutes. For special uses in which a partially cured (vulcanized) rubber is desirable (for example, a. flexible material for shoe soles) the plasticizers of Examples I and II had specific advantages over the plasticizer recovered from the lubricating oil-sulfuric acid sludge in the presence of which the rate of cure was more rapid.

EXAMPLE 1v Other tests were made in which a fraction of the plasticizer oil of Example I boiling from 300" to 400 C. was used in the production of shoe sole material from a rubber compounding mixture containing a high proportion of butadienestyrene copolymer. Comparative results were also obtained on a blank mixture containing no plasticizer. The test composition used consisted of 30 parts by welght-df' GR S50fl20 parts by (a filler comprising hydrated -'calcium silicate),

1 part by' weig'ht of'ethylene glycol, 1 part by weight of paraffin, 2 'part'sby'weig'hto-f sulfur, 0.75 'partby weight of 'Cumate ta'n accelerator consisting of cupric-diethyldithiocarbamate") and 5- parts by weight of plasticizer 'oil, except in blank runs in which no plasticizer was used.

' The results of these tests are 'given inTable TABLE 4 Taste of plasticizersin s'ltoe sole s-tock 1300-400" (Direction of plasticizer from polymer gasoline-hydrogen fluoride treatmentJ PHYSICAL PROPERTIES s 1 T E 'rn n Press cure, Minutes U. S. BUREAU OF STANDARDS ABRASION l Abrasion Flex.

41, 500+ 39; 500+ 500+ 9+ l .J. L

t Specific Gravity A 1:221

[No plasticizer used] PHYSICAL PROPERTIES S T E TR H Press cure, Minutes U. S BUREAU OF STANDARDS ABRASION Abrasion Flex.

Press cure, Minutes 320 F.:

Specific Gravity 1.234

Standards abrader) and the crack growth resistsince (Ross flexing machine) oi' thestock, contai'ning'my 'plasticiz'er,- are quite high. With 'rein the presan'c'e Quid hydrogen {fluoride at a temperature 'of'irorn about 0 to about 150' C.

at least one aliphatic hydrocarbon selected from the group consisting of iscparaflinic andoleflnic hydrocarbons, separating the resultant reaction roducts into a hydrocarbon layer and a hydrogen fluoride layer. recovering a substantially fluorine-free hydrocarbon material f'ro'nr said hydrogen fluoride layer, and removing from said last-named material the hydrocarbons boiling below about C. to leave said residue, and (2) the reaction'product of sulfur with said hydrocarbon residue.

'2. A composition of'matte'r comprising a rubber selected from the group consisting of natural rubber, butadie'ne-styrene copolymers, butadieneacrylonitrile copolymers, and butadiene-i'sobutylene copolymers, and an unsaturated polycyclic hydrocarbon residue containing conjugated unsaturation and produced by reacting an olefinic hydrocarbon in the presence of liquid hydrogen fluoride at a temperature of from about 0 to about 150 0., separating the resultant reaction product into a hydrocarbon layer and a hydrogen fluoride layer, recoveringa substantially fluorinefree hydrocarbon material from' said hydrogen fluoride layer, removing from said substantially fluorine-free hydrocarbon material the hydrocarbons boiling below about 150 C. to leave said residue.

3. A composition of matter comprising a rubber selected from the group consisting of natural rubber, butadiene-styrene copolymers, butadieneacrylonitrile copolymers, and butadiene-isobutylene copolymers, and an unsaturated polycyclic hydrocarbon residue containing conjugated unsaturation and produced by reacting a branched chain parafiinic hydrocarbon in the presence of liquid hydrogen fluoride at a temperature of from about 30 to about 150 C., separating the resultant reaction product into a hydrocarbon layer and a hydrogen fluoride layer, recovering a substantially fluorine-free hydrocarbon material from said hydrogen fluoride layer, removing from said substantially fluorine-free hydrocarbon material the hydrocarbons boiling below about 150 C. to leave said residue.

4. A composition of matter comprising a rubber selected from the group consisting of natural rubber, butadiene-styrene copolymers, butadleneacrylonitrile copolymers, and butadiene-isobutylene copolymers and from about 5 to about 30% by weight of a plasticizer comprising essentially an unsaturated polycyclic hydrocarbon mixture boiling above about 150 C. and produced by reacting an olefinic hydrocarbon having at least four carbon atoms per molecule with liquid hydrogen fluoride at a temperature of from about 0 to about 150 C.

- 5. A vulcanized rubber-like material from'the roup consisting of natural rubber, butadienestyrene copolymers, butadiene-acrylonitrile copolymers and butadiene-isobutylene copolymers containing an unsaturated polycyclic hydrocarbon residue containing conjugated unsaturation and produced by reacting a monoolefinic hydrocarbon having at least four carbon atoms per molecule in the presence of liquid hydrogen fluoride at a temperature of from about 0 to about 150 C., separating the resultant reaction products into a hydrocarbon layer and a hydrogen fluoride layer, recovering a substantially fluorine-free hydrocarbon material from said hydrogen fluoride layer, removing from said substantially fluorine-free hydrocarbon material the hydrocarbons boiling below about 150 C. to leave said residue.

6. The composition defined in claim 2 further characterized in that the rubber comprises natural rubber. I

'7, The composition defined in claim 2 further characterized in that the rubber comprises a copolymer of butadiene and styrene.

, 8. The composition defined in claim 2 further characterized in that the rubber comprises a copolymer of butadiene and isobutylene.

9. A covulcanized mixture of a butadienestyrene copolymer, sulfur, and a plasticizer oil,

the latter comprising essentially an unsaturated polycyclic hydrocarbon residue produced by reacting a normally liquid monoolefinic hydrocarbon in the presence of liquid hydrogen fluoride at a temperature of from about 0 to about 150 0., separating the resultant reaction product into a hydrocarbon layer and a hydrogen fluoride layer, recovering a substantially fluorine-free hydrocarbon material from said hydrogen fluoride layer, removing from said substantially fluorine-free hydrocarbon material the hydrocarbons boiling below about 150 C. to leave said residue.

10. A covulcanized mixture of a butadiene- 16 styrene copolymer, sulfur,- and a plasticizer oil, the latter comprising essentially an unsaturated polycyclic hydrocarbon residue produced by .reacting a normally liquid monoolefinic hydrocarbon in the presence of liquid hydrogen fluoride at a temperature of from about 0 to about C., separating the resultant reaction product into a hydrocarbon layer and a hydrogen fluoride layer, recovering a substantially fluorinefree hydrocarbon material from said hydrogen fluoride layer, removing from said substantially fluorine-free hydrocarbon material the hydrocarbons boiling below about 300 C. to leave said residue.

HERMAN s. BLOCH,

REFERENCES CITED The following references are of record in the file of this patent:

V UNITED STATES PATENTS Number Name Date 2,008,102 Hyman July 16, 1935 2,008,103 Hyman July 16, 1935 2,371,341 Matuszak Mar. 13, 1945 2,400,521 Kuhn May 21, 1946 2,422,002 Elwell et al. June 10, 1947 2,433,849 Lathrop Jan. 6, 1948 2,440,477 Johnstone Apr. 2'7, 1948 

1. A COMPOSITION OF MATTER COMPRISING A RUBBER SELECTED FROM THE GROUP CONSISTING OF NATURAL RUBBER, BUTADIENE-STYRENE COPOLYMERS, BUTADIENEACRYLONITRILE COPOLYMERS, AND BUTADIENE-ISOBUTYLENE COPOLYMERS, AND A PLASTICIZER SELECTED FROM THE GROUP CONSISTING OF: (1) AN UNSATURATED POLYCYCLIC HYDROCARBON RESIDUE CONTAINING CONJUGATED UNSATURATION AND PRODUCED BY REACTING IN THE PRESENCE OF LIQUID HYDROGEN FLUORIDE AT A TEMPERATURE OF FROM ABOUT 0* TO ABOUT 150* C. AT LEAST ONE ALIPHATIC HYDROCARBON SELECTED FROM THE GROUP CONSISTING OF ISOPARAFFINIC AND OLEFINIC HYDROCARBONS, SEPARATING THE RESULTANT REACTION PRODUCTS INTO A HYDROCARBON LAYER AND A HYDROGEN FLUORIDE LAYER, RECOVERING A SUBSTANTIALLY FLUORINE-FREE HYDROCARBON MATERIAL FROM SAID HYDROGEN FLUORIDE LAYER, AND REMOVING FROM SAID LAST-NAMED MATERIAL THE HYDROCARBONS BOILING BELOW ABOUT 150* C. TO LEAVE SAID RESIDUE, AND (2) THE REACTION PRODUCT OF SULFUR WITH SAID HYDROCARBON RESIDUE. 